U.S. Severe Weather Forecast (Coup d'œil sur la convection)

Day Three

acus01 kwns 282000 
Storm Prediction Center ac 281958 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0258 PM CDT Monday Jul 28 2014 

Valid 282000z - 291200z 

..there is a slight risk of severe thunderstorms for parts of New England... 

..There is a slight risk of severe thunderstorms for parts of the southeast... 

Strong to severe storms with damaging winds as the primary hazard 
will remain possible into this evening across parts of New England 
and the southeast. 

..ern Carolinas to the central Gulf Coast... 
Scattered storms are developing along a cold front from the S 
Atlantic Coastal Plain towards the lower MS valley. Surface 
temperatures in the 90s have yielded a moderate to strongly unstable 
air mass in the warm sector with MLCAPE of 1500-3000 j/kg. Veered 
surface winds ahead of the front will remain a limiting factor to 
greater vertical shear...in addition to predominately parallel 
orientation of deep-layer flow with the trailing portion of the 
front. For these reasons...have trimmed western extent of slight risk 
from the central Gulf Coast. 

..New England... 
Clusters of storms have developed ahead of the compact upper low and 
should evolve NE across New England through about 00z. This type of 
Mode should support isolated damaging winds and marginally severe 
hail. Have made a minor adjustment to align slight risk with the 
expected surface cyclone track into western ME...with rapid weakening of 
the threat still anticipated just after sunset. 

.Grams.. 07/28/2014 

Previous discussion... /issued 1121 am CDT Monday Jul 28 2014/ 

..eastern Carolinas into southern MS/al... 
A large upper trough has become established over the eastern United 
States...with the main cold front now extending from NC into the 
Gulf Coast states. Ample low level moisture and strong heating will 
yield a moderately unstable air mass ahead of the front this 
afternoon from eastern NC/SC into parts of GA/al/MS. Thunderstorms 
are expected to develop along/ahead of the front and near sea breeze 
boundaries. Forecast soundings show rather strong winds aloft from 
Georgia northeastward...where organized/supercell storm structures are 
possible. This area is most likely to see locally severe storms 
capable of damaging winds and hail. Farther westward...vertical 
shear profiles are weaker...but potential will remain for a isolated 
severe storms with damaging winds the main threat. 

..New England... 
A compact upper low is moving northeastward across New York. A middle level 
dry slot is rotating around the east side of the low...where some 
daytime heating and steepening lapse rates will occur this 
afternoon. Residual dewpoints in the 60s and cooling temperatures 
aloft will promote cape values of 500-1000 j/kg. Forecast soundings 
appear favorable for a few strong/severe storms capable of large 
hail and damaging winds. A brief tornado cannot be ruled out. The 
threat should end rather quickly after sunset. 

Mesoscale Discussion

acus11 kwns 281828 
sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 281827 

Mesoscale discussion 1498 
National Weather Service Storm Prediction Center Norman OK 
0127 PM CDT Monday Jul 28 2014 

Areas affected...southern NC/southern and eastern SC/central Georgia/parts of southern Alabama 

Concerning...severe potential...watch possible 

Valid 281827z - 282000z 

Probability of watch issuance...40 percent 

Summary...increasing storm coverage within an environment supportive 
of low-end severe risk may necessitate ww issuance across parts of 
the discussion area. 

Discussion...latest surface and objective analyses show a 
moist/destabilizing airmass ahead of an east-northeast-west-southwest cold front extending 
from southern/eastern NC to southern MS. Showers and thunderstorms have begun 
developing over the past hour or so near and ahead of the 
front...and should continue to increase in coverage/intensity this 
afternoon. With moderate/roughly unidirectional westerly flow aloft 
observed across the area...a few organized/esewd-moving storm 
clusters should evolve with time -- posing some risk for marginal 
hail and strong/gusty winds. We will continue to monitor convective 
evolution across the region -- where any concentration of stronger 
convective development could require ww consideration. 

.Goss/Hart.. 07/28/2014 

..please see www.Spc.NOAA.Gov for graphic product... 


Latitude...Lon 33937772 33137930 31928099 31368623 31678776 32068828 
33008503 33368186 34417814 33937772